This disclosure relates generally to the field of image processing. More particularly, this disclosure relates to techniques to combine or fuse multiple images to generate a single (composite) output image using intensity mapping functions.
Stand-alone cameras and other electronic devices having image capture capability (e.g., mobile telephones and tablet computer systems) are able to capture multiple, successive images of a scene. These captures can occur under various conditions. For example, a camera can be used to capture a sequence of images taken at the same exposure, a sequence of images taken at different exposures, two consecutive images using different capture parameters (e.g., one captured with a flash, the other without the flash), etc. Further, multiple imaging devices each employing a different sensor may also be used in the capture process.
Once such images are in hand, one objective can be to combine or fuse them to produce an agreeable image that achieves a desired objective. Examples include, but are not limited to, fusing information from multiple images to reduce image noise or to produce a new high dynamic range (HDR) image with a wider dynamic range than any of the single images, and to improve picture detail in low light conditions such as in a flash/no flash image capture pair. Inherent in each of these examples is the existence of a time delay between successive image captures. Because of this, a common, re-occurring issue manifests itself: local motion. Local motion may express itself as blurring or ghosting in fused images.